[ARC5] N-1 Carbon Mic Element and T-17s

[Richard Knoppow]

----- Original Message ----- 
From: "David Stinson" <arc5 at ix.netcom.com>
To: <milsurplus at mailman.qth.net>; "ARC-5 List" 
<arc5 at mailman.qth.net>
Sent: Sunday, October 21, 2012 11:40 AM
Subject: [ARC5] N-1 Carbon Mic Element and T-17s


> Re: Using T-17 mics.
> I've found exactly one T-17 that would deliver usable
> audio to a BC-456.  No amount of bashing or baking
> (or cussing) did any good with the others.
> So I temporarily hung a telephone element in the case,
> which does not fit inside but works, waiting for a better 
> idea.
>
> Came across a few small carbon mic elements
> in round cardboard containers labeled:
> "ONE N-1 TRANS. UNIT"
> IIRC, these are used used in some 50s-60s handsets.
> I gave them a "table bump",removed the thick rubber
> moisture barrier and replaced it with light fabric,
> then hot-glued the elements in place of a couple
> of stone-dead and unrecoverable T-17 carts,
> with some "stuffing" behind to fill the chamber.
> To my surprise, through the small-diameter holes
> in the T-17 face, these  elements delivered ample audio
> to a BC-456 modulator.  In fact, I can over-modulate.
>
> Are these elements available and at reasonable prices?
>
> TNX ES 73 DE Dave AB5S

     Dave, the N-1 is the element from the standard 
telephone operator's boom set.  These were standard on 
switchboards and also sold for use on television private 
line use, usually with a second, split, headphone.
     I can't remember if the T-17 has a sealed element. If 
not you may be able to replace the carbon.  The old T-1 type 
WE element has a lot of carbon granules in it and is pretty 
well sealed.  You can also try baking the _carbon_.  The 
entire microphone will not take enough heat to dry the 
carbon granules. I don't know if this is a sure fire fix but 
is worth trying. If NOS elements can be found their 
condition will depend on how they are packed. If well sealed 
against moisture they will be like new. If moisture has 
gotten to the they won't be any better than what you have.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com